The present invention relates to a disk drive mechanism, and more particularly, to a disk drive apparatus which can be made thinner than conventional ones. Generally, a 3.5" flexible disk medium (hereinafter called a "disk") 1 has a disk main body 2 with a metallic hub 3 provided in the center thereof as shown in FIG. 1, and the hub 3 has a rectangular chucking hole 4 and an oval shaped locating hole 5 provided on the hub. When the disk 1 is loaded in a disk drive 10, a spindle 6 and a drive pin 7 of the drive apparatus are inserted respectively into the chucking hole 4 and locating hole 5. The spindle 6 and the drive pin 7 are positioned to touch internally the chucking hole 4 and the locating hole 5 respectively with their respective circumferences as shown in FIG. 1. When the drive pin 7 and spindle 6 rotate, the main body 2 is drivingly rotated while being positioned at a rotating center position by the spindle 6 and the drive pin 7.
FIG. 2 shows a sectional view taken along line II--II in FIG. 1. The spindle 6 is rotated by a spindle motor 8 which is comprised of a stator 8a and a rotor 8b. Tables 9a and 9b for mounting the hub 3 of the disk 1 are fixed on the spindle 6. The drive pin 7 is provided on the table 9a. The hub 3 is mounted on top faces 9c and 9d. And a chucking magnet 11 is provided on the table 9a. The chuck magnet 11 maintains the hub 3 in a secure state on the top faces 9c and 9d of the tables 9a and 9b.
The chucking hole 4 has a square shape as shown in FIG. 1 and FIG. 2. The spindle 6 contacts both of two sides of an inner side surface portion 4a of the chucking hole 4. And the spindle 6 has a contact portion 6a whose height A1 is substantially equal to the height of an inner face 4b of the inner side surface portion 4a which contacts the spindle 6. The height A1 is a dimension from the top face 9c to an upper end of columnar surface of an contact portion 6a.
A dome like spherical shaped tip 6b is provided on the contact portion 6a. The tip 6b guides the spindle 6 to the chucking hole 4 as the spindle 6 is being inserted in the chucking hole 4. The height of the tip 6b is indicated as A2 in FIG. 2.
In the case where the disk 1 is to be set into the disk drive 10 having the spindle 6 constructed as described above described, the disk 1 is inserted into disk the drive 10, in a state where a lower disk case plate 1a (where the hub 3 is exposed) is positioned higher than the tip 6b of the spindle 6, till the disk 1 reaches a specified position. When the disk 1 is inserted to the specified position where the chucking hole 4 of the hub 3 corresponds to the spindle 6, the disk 1 drops down, and the spindle 6 is relatively inserted into the chucking hole 4.
In the disk drive 10, as described above, the spindle 6 has the contact portion 6a having the height A1 and the tip 6b having the height A2. Further the disk drive 10 needs a space (A3 shown in FIG. 2) in which the disk 1 can move along a level higher than the tip 6b when the disk 1 is being loaded in the disk drive 10. Accordingly, the conventional disk drive 10 needs a height (axial length) of (A1+A2+A3) in the axial direction of the spindle 6 above the top face 9c, and this factor precludes any disk drive from being made thinner in construction.